Frequency spectral management apparatus and method, geographical location database and secondary system apparatus

ABSTRACT

A system that receives a request for resources from a first system of a plurality of systems having different levels of priority; identifies resources that are available in a second system different from the plurality of systems based on the received request; and determines whether to adjust a resource assigned to the plurality of systems based on the priority level of the first system and the resources that are available in the second system.

FIELD OF THE INVENTION

The present invention generally relates to the field of wirelesscommunication, and particularly relates to frequency spectral managementin a radio system. More particularly, the present invention relates to afrequency spectral management apparatus, a geographical locationdatabase, a secondary system apparatus and a frequency spectralmanagement system including these apparatus as well as a frequencyspectral management method, for achieving reasonable usage of frequencyspectral resources in a cognitive radio system.

BACKGROUND OF THE INVENTION

With the evolution of the wireless communication system, the users havehigher and higher demand for services with high quality, high speed andnew services. The wireless communication operators and equipmentmanufacturers are required to continuously improve systems to meet theusers' demand. It requires a large amount of frequency spectralresources (The frequency spectral resources can be evaluated numericallyfor example with parameters such as time, frequency, bandwidth,allowable maximum emission power.) to support new services and satisfythe demand for high speed communication. However, the frequency spectralresources are limited, and are already distributed to fixed operators orservices. New available frequency spectral resources are either rare orquite expensive.

In this context, the concept of dynamic frequency spectral usage isproposed, where those frequency spectral resources already authorized(distributed) to some services but not sufficiently made use of aredynamically utilized. The current cognitive radio system is based onthis idea. The cognitive radio system can automatically detect thesurrounding wireless environments, and allow other users or systems(secondary users or secondary systems) to make use of frequency spectralresources for an authorized user or system (primary user or system) inthe case that no harmful interferences will be caused to the authorizeduser or system. With the development of the cognitive radio system,various secondary systems will access to request the usage of thefrequency spectral resources for the primary system in the future, andit is necessary to solve the problem of coordinating the frequencyspectral resources allocation among various types of secondary systemsefficiently in the case that competition occurs among a plurality ofsecondary systems.

SUMMARY OF THE INVENTION

In the following, an overview of the present invention is given simplyto provide basic understanding to some aspects of the present invention.It should be understood that this overview is not an exhaustive overviewof the present invention. It is not intended to determine a criticalpart or an important part of the present invention, nor to limit thescope of the present invention. An object of the overview is only togive some concepts in a simplified manner, which serves as a preface ofa more detailed description described later.

In view of the above demand, the present invention aims to provide afrequency spectral management apparatus and a frequency spectralmanagement method, which divides priority levels for the secondarysystems coexisting with the primary system that competes with each otherin the cognitive radio system and manage the frequency spectral usage ofsecondary systems with different priority levels. The presentapplication also provides a geographical location database with arelatively simplified function which cooperates with the frequencyspectral management apparatus, corresponding secondary system apparatusin the secondary systems, and a frequency spectral management systemincluding the frequency spectral management apparatus, the geographicallocation database and the secondary system apparatus.

According to an aspect of the present invention, a system is providedthat receives a request for resources from a first system of a pluralityof systems having different levels of priority; identifies resourcesthat are available in a second system different from the plurality ofsystems based on the received request; and determines whether to adjusta resource assigned to the plurality of systems based on the prioritylevel of the first system and the resources that are available in thesecond system.

The system realizes efficient usage of the frequency spectral resourcesby dividing the secondary systems into different priority levels,processing the frequency spectral usage requests of secondary systemswith different priority levels, and adjusting the frequency spectralused by the secondary systems with a low priority level.

These and other advantages of the present invention will be moreapparent by illustrating in detail a preferred embodiment of the presentinvention in conjunction with accompanying drawings below.

BRIEF DESCRIPTION OF THE DRAWINGS

To further set forth the above and other advantages and features of thepresent invention, detailed description will be made in the followingtaken in conjunction with accompanying drawings in which identical orlike reference signs designate identical or like components. Theaccompanying drawings, together with the detailed description below, areincorporated into and form a part of the specification. It should benoted that the accompanying drawings only illustrate, by way of example,typical embodiments of the present invention and should not be construedas a limitation to the scope of the invention. In the accompanyingdrawings:

FIG. 1 is a schematic drawing illustrating the constitution of acognitive radio system according to an embodiment of the invention;

FIG. 2 shows the structural block diagram of the frequency spectralmanagement apparatus in the cognitive radio system according to anembodiment of the invention;

FIG. 3 shows the structural block diagram of the frequency spectralusage adjusting unit in the frequency spectral management apparatusaccording to an embodiment of the invention;

FIG. 4 is a schematic drawing illustrating how to select an existingsecond level secondary system to be adjusted;

FIG. 5 is a schematic drawing illustrating the equivalent interferencelines for selecting an existing second level secondary system to beadjusted;

FIG. 6 shows the structural block diagram of the frequency spectralmanagement apparatus in the cognitive radio system according to anotherembodiment of the invention;

FIG. 7 is a schematic drawing illustrating the constitution of acognitive radio system according to another embodiment of the invention;

FIG. 8 shows the structural block diagram of the geographical locationdatabase in the cognitive radio system according to an embodiment of theinvention;

FIG. 9 shows the information flow in the cognitive radio system when thetarget secondary system is a second level secondary system;

FIG. 10 shows the information flow in the cognitive radio system whenthe target secondary system is a first level secondary system;

FIG. 11 shows the structural block diagram of the secondary systemapparatus in the cognitive radio system according to an embodiment ofthe invention;

FIG. 12 shows the flowchart of the frequency spectral management methodin the cognitive radio system according to an embodiment of theinvention;

FIG. 13 shows the flowchart of the sub-steps of the frequency spectraladjusting step in the frequency spectral management method according toan embodiment of the invention;

FIG. 14 is a detailed flowchart for the frequency adjusting performedwhen the target secondary system is a first level secondary system; and

FIG. 15 is an exemplary block diagram illustrating the structure of ageneral purpose personal computer capable of realizing the method and/orapparatus and/or system according to the embodiments of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

An exemplary embodiment of the present invention will be describedhereinafter in conjunction with the accompanying drawings. For thepurpose of conciseness and clarity, not all features of an embodimentare described in this specification. However, it should be understoodthat multiple decisions specific to the embodiment have to be made in aprocess of developing any such embodiment to realize a particular objectof a developer, for example, conforming to those constraints related toa system and a business, and these constraints may change as theembodiments differs. Furthermore, it should also be understood thatalthough the development work may be very complicated andtime-consuming, for those skilled in the art benefiting from the presentdisclosure, such development work is only a routine task.

Here, it should also be noted that in order to avoid obscuring thepresent invention due to unnecessary details, only a device structureand/or processing steps closely related to the solution according to thepresent invention are illustrated in the accompanying drawing, and otherdetails having little relationship to the present invention are omitted.

Cognitive Radio System

First, the cognitive radio system where the frequency spectralmanagement apparatus is located is simply described. Generally, thecognitive radio system includes a primary system and secondary systems.The primary system is a system with right to use the frequency spectral,which can includes multiple users (primary users). The secondary systemcan be a system without right to use the frequency spectral which canperform communication using the frequency spectral appropriately onlywhen the primary system does not use the frequency spectral. Thesecondary system can have multiple users (secondary users).Alternatively, the secondary system can also be a system with right touse the frequency spectral but have a lower priority level than theprimary system in the using of the frequency spectral. For example, whenthe operators deploy new base stations to provide new services, theexisting base station and the provided services are taken as the primarysystem, having priority in using the frequency spectral.

To be noted, the available frequency spectral resources here can bereferred as time, frequency band, transmission power, etc.

FIG. 1 shows a schematic drawing illustrating the constitution of acognitive radio system 100 according to an embodiment of the invention,as an application instance. In the cognitive radio system 100, since theTV broadcast frequency spectral itself is allocated to the TV broadcastsystem, therefore, the TV broadcast system is the primary system 101,including a primary user base station 1011 and multiple primary users(televisions) 1012. The mobile communication system 102, 103 and 104 aresecondary systems, including secondary user base stations 1021, 1031,1041 and secondary users 1022, 1032, 1042 respectively. In the cognitiveradio system 100, the frequency spectral of a channel where no programis broadcast or the frequency spectral of an adjacent channel in thedigital TV broadcast frequency spectral can be dynamically used andwireless mobile communication can be performed, in the case of notinterfering the receiving of the TV signals.

Specifically, UHF frequency band is allocated to the TV broadcastservice, and thus the TV broadcast system has the highest priority levelin this frequency band and is the primary system. In addition, thefrequency spectral resources in the UHF which are not used in a timeperiod and in an area by the TV broadcast system can be allocated toother communication system for use.

Such a communication manner of primary system and secondary systemscoexisting requires that the applications of the secondary systems donot produce negative affect on the applications of the primary system.In other words, the affect incurred by the frequency spectral usage ofthe secondary systems can be controlled within the primary systemallowable range. In the situation that the interference to the primarysystem is maintained within certain range, that is, does not exceed theprimary system's threshold, a plurality of secondary systems can sharethe frequency spectral resources for the primary system which can beused by these system.

Those skilled in the art can understand that, although FIG. 1 shows thecase of the primary system being the TV broadcast system, the presentapplication is not limited to this, and the primary system can also be amobile communication system with the right of frequency spectral usage,while the secondary systems can also be other systems requiring to usethe frequency spectral resources to perform communication, such as thesmart meter reading system. In addition, the number of mobilecommunication system is not limited to 3, but can be more or less.

Currently, one of the main manners for protecting the primary system isto store the coverage information of the primary system into a database,which further stores the interference threshold the primary system canallow. The secondary system in the same as area as that the primarysystem is located first has to access this database and submit the stateinformation of the secondary system such as position information,spectrum emission mask, transmission bandwidth and carrier frequency,before beginning to make use of the frequency spectral for the primarysystem. Then, the database calculates the amount of interference to beproduced by the secondary system to the primary system according to thestate information of the secondary system, and compute the pre-estimatedavailable frequency spectral resources for the secondary system underthe current state according to the calculated amount of interference thesecondary system produced to the primary system under the current state.

Frequency Spectral Management Apparatus

In FIG. 1, the cognitive radio system 100 can adopt the frequencyspectral management apparatus 105 to manage the allocation of frequencyspectral resources among different secondary systems.

According to an embodiment of the application, the cognitive radiosystem 100 comprises a primary system 101, a first level secondarysystem (for example, the secondary system 102), and a second levelsecondary system (for example, the secondary system 103, 104), the firstlevel secondary system making use of frequency spectral resources forthe primary system with a higher priority level than the second levelsecondary system. As shown in FIG. 2, the frequency spectral managementapparatus 105 in the cognitive radio system 100 includes: acommunication unit 501, configured to receive information of a targetsecondary system requesting usage of the frequency spectral resourcesfor the primary system; an available frequency spectral acquiring unit502, configured to acquire pre-estimated available frequency spectralfor the target secondary system; and a frequency spectral usageadjusting unit 503, configured to determine adjustment with respect tothe pre-estimated available frequency spectral for the target secondarysystem so as to determine available frequency spectral for the targetsecondary system, and/or determine adjustment with respect to thefrequency spectral used by existing second level secondary systems,according to the priority level of the target secondary system.

In addition, the frequency spectral usage adjusting unit 503 can furtherprovide the adjusting information to the communication unit 501, so asto provide the same directly or via the geographical location databaseto be mentioned latter to corresponding secondary systems. For example,the frequency spectral usage adjusting unit 503 can be configured toadjust the frequency spectral usage of the corresponding existing secondlevel secondary systems according to the determined adjustment withrespect to the frequency spectral used by the existing second levelsecondary systems.

In the cognitive radio system 100, the secondary systems are classifiedinto the first level secondary systems and the second level secondarysystems according to their priority levels in the terms of the frequencyspectral usage. The priority level of the first level secondary systemsis higher than that of the second level secondary systems. Bycontrolling their usage of the frequency spectral resources for theprimary system according to the priority levels of the secondarysystems, the communication quality of the secondary systems with a highpriority level can be ensured as much as possible, and the availablefrequency spectral resources to the secondary systems with a lowpriority level can be maximized in the case that the secondary systemswith a high priority level do not use the frequency spectral.

The priority levels of the secondary systems can be preset in advance,or vary according to the variation of the application types of thesystems. For example, a mobile communication system with QoS guarantee(for example, using the frequency spectral resources for the primarysystem by paying) provided by the operators is a first level secondarysystem, and a system without QoS guarantee which uses the frequencyspectral randomly (for example, using the frequency spectral resourcesfor the primary system for free) is a second level secondary system.However, the setting of the priority level of a secondary system is notlimited thereto, and can be set according to the practical application.

When a target secondary system (for example, can be any one of thesecondary systems 102, 103 and 104) files a request for using thefrequency spectral resources for the primary system 101 to the frequencyspectral management apparatus 105 directly, the communication unit 501in the frequency spectral management apparatus 105 receives this requestinformation, and provides it to the available frequency spectralacquiring unit 502. The request information includes related informationregarding the target secondary system. Further, as will be discussed inthe embodiments hereinafter, this request is not necessary to bereceived from the target secondary system directly, but can also comefrom the geographical location database in the cognitive radio system.

As an example, the request information can include priority informationof the secondary system explicitly. Alternatively, the requestinformation can include only identification (ID) of the secondarysystem, and the frequency spectral management apparatus 105 query astored list of system IDs and corresponding priority levels according tothis ID to determine the priority level of the secondary system. Itshould be understood that the kinds of information which can becontained in the request information are not limited thereto.

For example, the request information can include the geographicallocation of the target secondary system. In addition, the requestinformation can further include system parameters of the targetsecondary system, the quality requirement of the frequency spectralusage of the target secondary system and the interference threshold forthe target secondary system, etc.

The available frequency spectral acquiring unit 502 acquires thepre-estimated available frequency spectral for the target secondarysystem in response to the received request information, to preliminarilyconfirm the frequency spectral which may be used by the target secondarysystem according to the interference the primary system 101 is subjectedto.

In an embodiment, the available frequency spectral acquiring unit 502 isconfigured to acquire the pre-estimated available frequency spectralunder a condition that interference the primary system is subjected tois expected not to exceed an interference threshold for the primarysystem when the target secondary system makes use of the frequencyspectral resources for the primary system.

Specifically, the available frequency spectral acquiring unit 502 canacquire the pre-estimated available frequency spectral by calculating onthe basis of the request information, or acquire information about thepre-estimated available frequency spectral from an outside databasedirectly. The calculating of the pre-estimated available frequencyspectral can be achieved by virtue of any prior art.

Then, the frequency spectral usage adjusting unit 503 determinesadjustment with respect to the pre-estimated available frequencyspectral for the target secondary system, and further determinesadjustment with respect to the frequency spectral used by existingsecond level secondary systems as necessary, according to the prioritylevel of the target secondary system acquired based on the requestinformation. Subsequently, the adjusting information is provided to thecommunication unit 501, which feeds the adjusting information back tocorresponding secondary systems or the outer apparatus such as thegeographical location database which sends the request information.

By using the frequency spectral usage adjusting unit 503, it can beensured that the allocation of the frequency spectral resources to thetarget secondary system does not affect the frequency spectral usage ofthe existing primary system and secondary systems with a high prioritylevel. Moreover, the efficiency of the frequency spectral usage can bemaximized by allocating the frequency spectral resources according tothe priority levels of the secondary systems.

FIG. 3 shows the structural block diagram of the frequency spectralusage adjusting unit 503 according to an embodiment of the invention. Asshown in FIG. 3, the frequency spectral usage adjusting unit 503includes: a system priority level judging module 3001, configured tojudge the priority level of the target secondary system; an interferencecalculating module 3002, configured to calculate pre-estimatedinterferences existing first level secondary systems are subjected towhen the target secondary system makes use of the frequency spectralresources for the primary system in accordance with the pre-estimatedavailable frequency spectral therefor; and an adjusting module 3003,configured to determine adjustment with respect to the pre-estimatedavailable frequency spectral for the target secondary system so as todetermine the available frequency spectral therefor.

Wherein, the system priority level judging module 3001 can judge thepriority level of the target secondary system according to the requestinformation therefrom, and the specific manner depends on the type ofthe request information, as discussed above.

In order to keep the effect to the communication of the existing firstlevel secondary systems within a certain range, the interferencecalculating module 3002 estimates the pre-estimated interferences theexisting first level secondary systems are subjected to when the targetsecondary system performs communication making use of the pre-estimatedavailable frequency spectral therefor acquired by the availablefrequency spectral acquiring unit 502. Then, the adjusting module 3003determines adjustment with respect to the pre-estimated availablefrequency spectral for the target secondary system according to theresult of the estimating, so as to determine the frequency spectralwhich can be actually used by the target secondary system.

In one embodiment, the adjusting module 3003 determines frequencyspectral less than the pre-estimated available frequency spectral as theavailable frequency spectral for the target secondary system, in thecase that the pre-estimated interferences calculated by the interferencecalculating module 3002 exceed interference thresholds for the existingfirst level secondary systems. In other words, when the result ofestimating indicates that if the target secondary system performscommunication using the pre-estimated available frequency spectral,intolerable affect will be caused to the quality of communication of theexisting first level secondary systems, the adjusting module 3003reduces this pre-estimated available frequency spectral, for example, bya fixed amount or by an amount of frequency spectral corresponding tothe amount of interferences exceeding the each of the interferencethresholds for the existing first level secondary systems.

However, the following case might occur: when the target secondarysystem is a first level secondary system with QoS (Quality of Service)requirement, the reduction of the pre-estimated available frequencyspectral for the target secondary system will lead to a result that thequality of communication of the target secondary system cannot beguaranteed.

To solve this problem, if the system priority level judging module 3001judges that the target secondary system is a first level secondarysystem, the adjusting module is further configured to determineadjustment with respect to the frequency spectral used by the existingsecond level secondary systems on the basis of the requestinginformation of the target secondary system.

The following situation also may exist: if the target secondary systemis a first level secondary system, and the interferences caused by therespective existing secondary system to the target secondary systemexceed a pre-determined range so that the target secondary system cannotreach the expected communication quality, the adjusting module 3003 canreduce the frequency spectral used by the existing second levelsecondary systems. As such, on the one hand, the amount of interferencescaused by the existing second level secondary systems to the targetsecondary system can be reduced, and on the other hand, theinterferences caused by the existing second level secondary systems toprimary system can be reduced so that the amount of frequency spectralresources allowed to be allocated to the target secondary system can beincreased accordingly.

Further, if the pre-estimated interferences to the existing first levelsecondary systems exceed the interference thresholds in the case thatthe target secondary system performs communication using thepre-estimated available frequency spectral, it is necessary to reducethe pre-estimated available frequency spectral for the target secondarysystem, so that the target secondary system may not reach the expectedcommunication quality. In such a situation, the frequency spectral usedby the existing second level secondary systems can also be reduced.

Various manners can be adopted to adjust the frequency spectral used bythe existing second level secondary systems. One optional way is toreduce the frequency spectral used by all of the existing second levelsecondary systems, but the system overhead is high.

Therefore, one better way is to selectively adjust the existing secondlevel secondary systems. According to an embodiment of the presentapplication, the adjusting module 3003 is configured to select a secondlevel secondary system to be adjusted according to the followingprinciple: compared with reducing the frequency spectral used by theother second level secondary systems among the existing second levelsecondary systems, the available frequency spectral for the targetsecondary system can be increased more by reducing the frequencyspectral used by this second level secondary system.

Wherein, the adjusting module 3003 can be configured to reduce thefrequency spectral used by the selected one or more second levelsecondary systems to be adjusted by a fixed amount, or stop the one ormore second level secondary systems.

More particularly, the adjusting module 3003 can be configured to selecta second level secondary system to be adjusted according to a path lossor a distance from the existing second level secondary system to aprimary system reference point and a path loss or a distance from theexisting second level secondary system to the target secondary system.

FIG. 4 shows a schematic drawing illustrating how to select an existingsecond level secondary system to be adjusted. In FIG. 4, S2 denotes theexisting second level secondary systems, S1 denotes the existing firstlevel secondary systems and T0 denotes the target secondary system,which is a first level secondary system in this example. The referencepoint is a position in the service range of the primary system where theinterferences caused by the target secondary system are most serious.Although only two second level secondary systems and one first levelsecondary system (the target secondary system not included) are shown inFIG. 4, it is only for the purpose of clarity of illustration andexplanation. More generally, assuming there are totally N second levelsecondary systems and M first level secondary systems, the signal tonoise ratio (SNR) of the target secondary system can be expressed asfollows:

$\begin{matrix}{{SNR} = \frac{P_{0}}{{\sum\limits_{m = 1}^{M}{U_{m\; 0}P_{m}}} + {\sum\limits_{n = 1}^{N}{G_{n\; 0}P_{n}^{\prime}}} + \sigma_{n}^{2}}} & (1)\end{matrix}$

Wherein, P₀ is the maximum allowable transmission power for the targetsecondary system (the maximum available frequency spectral resourcescorresponding to a certain bandwidth at a certain location and at acertain time instance), and for example, P₀ can be the frequencyspectral acquired by the available frequency spectral acquiring unit502. P_(m) is the transmission power of an existing first levelsecondary system. U_(m0) is the path loss from the m-th first levelsecondary system to the target secondary system. P′_(n) is thetransmission power of an existing second level secondary system. G_(n0)is the path loss from the n-th second level secondary system to thetarget secondary system. σ_(n) ² is the Gaussian white noise of thereceiver of the target secondary system. In addition, FIG. 4 also showsthe path loss from the target secondary system to the reference point ofthe primary system as G_(0p), and the path loss from the n-th secondlevel secondary system to the reference point of the primary system asG_(np).

As can be seen from equation (1), reducing the transmission power P′_(n)of the existing second level secondary system can directly reduce thesecond item in the denominator. Meanwhile, it can be seen from FIG. 4that reducing the transmission power P′_(n) of the existing second levelsecondary system can reduce the amount of interferences at the referencepoint of the primary system so that the primary system can tolerate theinterference caused by the target secondary system at its referencepoint, that is, can increase the maximum allowable transmission powerfor the target secondary system indirectly. Assuming that thetransmission power of the existing second level secondary system isreduced by ΔP′_(n), the increase in the allowable transmission power forthe target secondary system is:

$\begin{matrix}{{\Delta \; P_{0}^{\prime}} = \frac{\Delta \; P_{n}^{\prime}G_{np}}{G_{op}}} & (2)\end{matrix}$

In conjunction with equation (1), it can be seen that when theadjustment is made to a second level secondary system with higher

${\frac{G_{np}}{G_{op}} + G_{n\; 0}},$

the improvement in the signal to noise ratio SNR of the target secondarysystem is more effective. As an example, to decrease the complexity ofadjusting, the second level secondary systems are ranked according totheir values of

$\frac{G_{np}}{G_{op}} + G_{n\; 0}$

in an order of from big to small, and then adjusted sequentially. SinceG_(0p) only depends on the locations of the target secondary system andthe corresponding reference point of the primary system, and do not varywith the selection of the second level secondary systems, therefore, ahigher

$\frac{G_{np}}{G_{op}} + G_{n\; 0}$

is equivalent to a higher G_(np)+G_(n0). In other words, a second levelsecondary system to be adjusted can be selected according to a path lossfrom the existing second level secondary system to a primary systemreference point and a path loss from the existing second level secondarysystem to the target secondary system.

Further, since the path loss increases as the distance decreases, themaximizing of the G_(np)+G_(n0) can be approximately equivalent to theminimizing of the sum of the distance from the existing second levelsecondary system to the target secondary system and the distance fromthe existing second level secondary system to a primary system referencepoint. In other words, a second level secondary system to be adjustedcan be selected according to a distance from the existing second levelsecondary system to a primary system reference point and a distance fromthe existing second level secondary system to the target secondarysystem.

Furthermore, the target secondary system and the primary systemreference point thereof can be taken as two foci F2 and F1, and anellipse is drawn by taking the sum of distances from any point in theplane to these two foci as a constant value. A series of ellipses can bedrawn corresponding to different constant values, referred as equivalentinterference lines, as shown in FIG. 5. That is, the effect ofinterferences on the same ellipse line is similar. In other words, theimprovements to the SNR of the target secondary system by adjusting thefrequency spectral usage of the second level secondary systems on thesame ellipse line are similar. Wherein, the value of

$\frac{G_{np}}{G_{op}} + G_{n\; 0}$

is larger for the second level secondary system located in the innercircle than the second level secondary system located in the outercircle. Therefore, a second level secondary system to be adjusted can beselected relatively intuitively according to the correspondence betweenthe geographical locations of the second level secondary systems and theellipses.

Further, in other embodiments, the frequency spectral usage adjustingunit 503 can further include a priority level adjusting module,configured to change the priority level of the target secondary systemto be the second level, in the case that there is no adjustable secondlevel secondary system or the requirement for the communication qualitycan still not be satisfied by adjusting the existing second levelsecondary systems.

After determining the second level secondary systems to be adjusted, thefrequency spectral management apparatus 105 can provide the adjustinginformation to the corresponding second level secondary systems via thecommunication unit 501. The corresponding second level secondary systemsadjust the frequency spectral being used accordingly, such as reducingthe frequency spectral by a fixed amount or stop using the frequencyspectral. The adjustment to the existing second level secondary systemscan be performed in real time.

In addition, it is generally required to set a period of validity forthe frequency spectral used by the secondary systems according to thetime when the primary system uses the frequency spectral. That is, thefrequency spectral can be used within a certain time range. In thiscase, the adjusting module 3003 can be further configured to storecorrespondence between the target secondary system and the selectedsecond level secondary systems to be adjusted in the case that it isnecessary to adjust the frequency spectral used by the existing secondlevel secondary systems, and after the target secondary system releasesthe frequency spectral, to restore the usage of the frequency spectralof the adjusted second level secondary systems, if the frequencyspectral used by the adjusted second level secondary systems beforeadjusting is still in the period of validity thereof, and therestoration will not impact other first level secondary systems.

The structure and function for each component of the frequency spectralmanagement apparatus 105 according to an embodiment of the presentapplication has been described above. It can be seen, by using thefrequency spectral usage adjusting unit 503 to determine the adjustmentto the pre-estimated available frequency spectral for the targetsecondary system and/or the frequency spectral used by the existingsecond level secondary systems, the second level secondary systems canbe efficiently controlled so that the first level secondary systems caneffectively make use of the frequency spectral. Further, the secondlevel secondary systems can acquire most frequency spectral resourceswithout affecting the communication of the first level secondarysystems.

Although FIG. 2 shown an exemplary structure of the frequency spectralmanagement apparatus 105, it is not limited thereto. The frequencyspectral management apparatus 105 can further other unit or combinationof units. As shown in FIG. 6, the frequency spectral managementapparatus 105 can further include a storage unit 504, configured tostore information related to at least one of the primary system, thefirst level secondary system and the second level secondary system,wherein, the related information includes geographical location of eachsystem, frequency spectral used by each system and the priority level ofeach system. In addition, the related information can further includethe quality requirement to the frequency spectral usage of respectivesystem and the interference threshold of respective system, etc, forexample especially for the first level secondary system with QoSguarantee. The communication unit 501, the available frequency spectralacquiring unit 502 and the frequency spectral usage adjusting unit 503are the same as those in FIG. 2 in structure and function, and thedescription thereof is omitted here.

The related information in the storage unit 504 can be used by theavailable frequency spectral acquiring unit 502 and/or the frequencyspectral usage adjusting unit 503 for calculation. Specifically, forexample, when the available frequency spectral acquiring unit 502 isconfigured to calculate the pre-estimated available frequency spectralby itself, it is possible to access this storage unit 504 to acquire therequired parameters such as the interference threshold for the primarysystem, the frequency spectral used by the existing secondary systemsand the geographical locations of the existing secondary systems, etc.

Likewise, the frequency spectral usage adjusting unit 503 can use thelocation of the existing secondary systems, the frequency spectral usedby the existing secondary systems and the priority levels thereof storedin the storage unit 504, to calculate the amount of interferences to beproduced to the existing first level secondary systems and the amount ofinterferences to be produced by the existing secondary systems to thetarget secondary system which is a first level secondary system when thetarget secondary system performs communication using the pre-estimatedavailable frequency spectral.

In one implementation, the storage unit 504 can further perform thefunction of checking whether the target secondary system sending out therequest is a valid secondary system, for example, of checking whetherthe target secondary system has passed some authentication.

Alternatively or additionally, as shown in FIG. 6 with dotted lines, thefrequency spectral management apparatus 105 can further include a systeminformation acquiring unit 505, configured to acquire informationrelated to at least one of the primary system, the first level secondarysystem and the second level secondary system from outside, wherein, therelated information includes geographical location of each system,frequency spectral used by each system and the priority level of eachsystem.

The wording outside herein means any component or system external to thefrequency spectral management apparatus 105. As an example, the systeminformation acquiring unit 505 can be further configured to acquireinformation related to at least one of the primary system, the firstlevel secondary system and the second level secondary system from ageographical location database.

In such a situation, the communication unit 501 is further configured toacquire the pre-estimated available frequency spectral from thegeographical location database by providing the related information ofthe target secondary system to the geographical location database.

In addition, although it is stated in the above that the relatedinformation includes geographical location of each system, frequencyspectral used by each system and the priority level of each system, thespecific content of the related information is not limited thereto. Forexample, the related information can further include system parametersand the interference threshold of each system, etc.

The frequency spectral management apparatus 105 described above can be aseparate apparatus, or for example can be located in the base station.Further, although FIG. 1 shows that the cognitive radio system 100 onlyincludes one frequency spectral management apparatus 105, this is justan example, and those skilled in the art can understand that, thecognitive radio system 100 can include a plurality of frequency spectralmanagement apparatus 105, which can operate by coordinating with exitingvarious methods.

Geographical Location Database

According to another embodiment of the present invention, besides thefrequency spectral management apparatus, the cognitive radio system canfurther include a geographical location database, as shown in FIG. 7.

In FIG. 7, the cognitive radio system 200 includes a primary system 101,a first level secondary system (for example, secondary system 102), anda second level secondary system (for example, secondary system 103,104), the first level secondary system making use of frequency spectralresources for the primary system with a higher priority level than thesecond level secondary system. The cognitive radio system 200 includes afrequency spectral management apparatus 105 and a geographical locationdatabase 201. Similarly, the number of the frequency spectral managementapparatus 105 and the geographical location database 201 is not limitedto one.

Wherein, the frequency spectral management apparatus 105 has thestructure and function described above with reference to FIG. 2, and therelated description will not be repeated herein. As shown in FIG. 8, thegeographical location database 201 includes: a communication part 2001,configured to receive information of a target secondary systemrequesting usage of the frequency spectral resources for the primarysystem; an available frequency spectral calculating part 2002,configured to calculate pre-estimated available frequency spectral forthe target secondary system in response to the information; and astorage part 2003, configured to store information related to theprimary system, the first level secondary system and the second levelsecondary system, wherein, the communication part 2001 transmits atleast the pre-estimated available frequency spectral to a frequencyspectral management apparatus 105 in the cognitive radio system 200, andreceives information related to adjustment with respect to thepre-estimated available frequency spectral for the target secondarysystem and/or information related to adjustment with respect to thefrequency spectral used by the existing second level secondary systemsdetermined by the frequency spectral management apparatus 105 accordingto a priority level of the target secondary system.

Optionally, the communication part 2001 can further send the relatedinformation of the target secondary system and the related informationof respective system stored in the storage part 2003 to the frequencyspectral management apparatus.

As an example, the geographical location database 201 can directly feedthe adjusting result, i.e., the available frequency spectral resourcesback to the target secondary system. Alternatively, the adjusting resultis fed back to the target secondary system by the frequency spectralmanagement apparatus 105, and the geographical location database 201just use the storage part 2003 to record the situation of the frequencyspectral allocation.

Wherein, the information related to the determined adjustment withrespect to the frequency spectral used by the existing second levelsecondary systems can be a frequency spectral usage adjusting commandcontaining the determined adjustment with respect to the frequencyspectral used by the existing second level secondary systems. Moreover,although not shown in FIG. 8, the geographical location database 201 canfurther include a frequency spectral usage adjusting unit, configured toadjust the frequency spectral usage of the corresponding existing secondlevel secondary systems according to the frequency spectral usageadjusting command.

In addition, the geographical location database 201 can further include:a period of validity setting part, configured to set a period ofvalidity for the pre-estimated available frequency spectral resourcesfor each second level secondary system according to the demand forfrequency spectral of the primary system, and divide the period ofvalidity into a plurality of valid time sections; and a timer,configured to perform timing so that the geographical location databasedetermines the available frequency spectral resources for each secondlevel secondary system at the time each valid time section expires, andperforms adjusting to the frequency spectral used by the correspondingsecond level secondary systems based on the information related to theadjustment.

As described above, the pre-estimated frequency spectral resources arecalculated under the condition that the interference the primary systemis subjected to is expected not to exceed an interference threshold forthe primary system. Taking the time when the primary system uses thefrequency spectral into account, the period of validity setting part canset a period of validity for the calculated pre-estimated availablefrequency spectral resources, to ensure the protection to the primarysystem. Meanwhile, to achieve more accurate management temporally, theperiod of validity can be further divided into valid time sections, andthe timer can start related processing at the time each valid timesection ends so that the geographical location database is capable ofdetermine for example the frequency spectral resources used by therespective second level secondary system can still be used, at whichtime it is also possible to perform adjustment with respect to thefrequency spectral used by the existing second level secondary systemsbased on the received adjusting information.

An example of the information flow among the geographical locationdatabase 201, the frequency spectral management apparatus 105 and thetarget secondary system when the target secondary system T0 which is asecond level secondary system requests the geographical locationdatabase 201 for using the frequency spectral resources for the primarysystem in the cognitive radio system 200 will be described below withreference to FIG. 9.

As shown in FIG. 9, the second level secondary system T0 sends a requestfor using the frequency spectral resources to the geographical locationdatabase 201. The geographical location database 201 calculates thepre-estimated available frequency spectral for the secondary system T0,and transmits the result of calculation and the related information ofthe second level secondary system T0 to the frequency spectralmanagement apparatus 105. The frequency spectral management apparatus105 first determines its priority level to be the second level, and thuscalculates the pre-estimated interferences the existing first levelsecondary system to be subjected to when the system T0 uses thepre-estimated available frequency spectral, so as to determine whetherto adjust or reduce the pre-estimated available frequency spectral sothat the pre-estimated interferences do not exceed the interferencethresholds for the existing first level secondary systems. Then, thefrequency spectral management apparatus 105 delivers the adjustinginformation to the geographical location database 201, which updates thepre-estimated available frequency spectral for the target secondarysystem according to the adjusting information, and feeds the informationback to the target secondary system T0 via the communication part 2001.Of course, as another example, the adjusting information can also be fedback to the second level secondary system T0 directly by the frequencyspectral management apparatus 105, as shown by the dotted lines.

In addition, FIG. 10 shows an example of the information flow among thegeographical location database 201, the frequency spectral managementapparatus 105 and the target secondary system when the target secondarysystem T0 which is a first level secondary system requests the frequencyspectral management apparatus 105 for using the frequency spectralresources for the primary system.

As shown in FIG. 10, the first level secondary system T0 sends out arequest for using the frequency spectral resources to the frequencyspectral management apparatus 105. The frequency spectral managementapparatus 105 acquires the desired communication quality and frequencyspectral using conditions (for example, the application range) by thefirst level secondary system T0, and the interference threshold, etc,and transmits the related information of the first level secondarysystem T0 to the geographical location database 201. The geographicallocation database 201 calculates the frequency spectral resources forthe primary system available to the target secondary system under thecondition that the protection for the primary system is ensured,according to the geographical location information and the like of thetarget secondary system, and then transmits this information to thefrequency spectral management apparatus 105. The frequency spectralmanagement apparatus 105 judges which of the existing second levelsecondary systems may cause interferences to the target secondary systemT0 (For example, the geographical location database 201 has transmittedthe information of the existing second level secondary systems to thefrequency spectral management apparatus in advance, such as at the timeof determining the frequency spectral resources used by each of thesecond level secondary systems.), according to the pre-estimatedfrequency spectral usage situation of the target secondary system andthe interference threshold thereof, and determines adjustment to thefrequency usage of the existing secondary systems and the targetsecondary system (the related method will be described in thefollowing). The frequency spectral management apparatus 105 for examplecan adopt the adjusting method described previously to select a secondlevel secondary system to be adjusted, so that the geographical locationdatabase 201 adjusts the corresponding second level secondary systemsand transmits the adjusting report back to the frequency spectralmanagement apparatus 105. At this time, the frequency spectralmanagement apparatus 105 can feed the available frequency spectralresources back to the target secondary system T0.

Although the example of information flow for the target secondary systemrequesting the frequency spectral management apparatus 105 and thegeographical location database 201 for using the frequency spectralresources for the primary system in the cognitive radio system has beendescribed with reference to FIG. 9 and FIG. 10 in the above, thespecific details are not limited thereto, and can be changed accordingto the structures and functions of the two correspondingly.

Secondary System Apparatus

The structure and function of the apparatus playing the role offrequency spectral management have been described above. It can beunderstood that the secondary system is necessary to include componentscapable of initiating a request and receiving the adjusting information.

Therefore, according to an embodiment of the application, there isfurther provided a secondary system apparatus 107 in a cognitive radiosystem, as described above, the cognitive radio system comprises aprimary system, a first level secondary system, and a second levelsecondary system, the first level secondary system making use offrequency spectral resources for the primary system with a higherpriority level than the second level secondary system, and the secondarysystem apparatus 107 is provided in the first level secondary system orin the second level secondary system. As shown in FIG. 11, the secondarysystem apparatus 107 includes: a communication unit 1071, configured totransmit requesting information of requesting usage of the frequencyspectral resources for the primary system, the requesting informationcontaining information about a priority level of the secondary systemapparatus, and receive available frequency spectral information for thesecondary system apparatus determined according to the priority level;and a frequency spectral using unit 1072, configured to make use of thefrequency spectral resources for the primary system according to theavailable frequency spectral information received by the communicationunit 1071.

Wherein, the information about a priority level of the secondary systemapparatus contains the information about the priority level of thesecondary system, that is, the information regarding whether thesecondary system is a first level secondary system or a second levelsecondary system.

When the secondary system apparatus 107 is corresponding to a secondlevel secondary system, the communication unit 1071 is furtherconfigured to receive frequency spectral usage adjusting informationregarding the secondary system apparatus 107, the frequency spectralusage adjusting information being determined according to the requestinginformation of the first level secondary system in the cognitive radiosystem requesting the usage of the frequency spectral resources for theprimary system. For example, there is the following case: when a newfirst level secondary system requests to use the frequency spectralresources, the frequency spectral management apparatus 105 may reducethe frequency spectral used by the second level secondary systemcorresponding to the secondary system apparatus 107 in response to therequest, and thus transmit an instruction for adjusting the frequencyspectral usage to the communication unit 1071 of the secondary systemapparatus 107.

Frequency Spectral Management System

According to the above disclosure of the present application, there isfurther provided a frequency spectral management system for managingfrequency spectral usage in a cognitive radio system, wherein, thecognitive radio system comprises a primary system, a first levelsecondary system, and a second level secondary system, the first levelsecondary system making use of frequency spectral resources for theprimary system with a higher priority level than the second levelsecondary system. The frequency spectral management system includes thefrequency spectral management apparatus 105, the geographical locationdatabase 201 and the secondary system apparatus 107 as described above.Wherein, the communication part 2001 in the geographical locationdatabase 201 transmits at least the pre-estimated available frequencyspectral to the frequency spectral management apparatus 105, andreceives information related to adjustment with respect to thepre-estimated available frequency spectral for the target secondarysystem and/or information related to adjustment with respect to thefrequency spectral used by the existing second level secondary systemsdetermined by the frequency spectral management apparatus 105 accordingto the priority level of the target secondary system. The specificinformation flow has been described above in detail with reference toFIG. 9 and FIG. 10, and will be omitted here.

By using this frequency spectral management system, the frequencyspectral resources for the primary system can be allocated morereasonably and the frequency spectral usage of the secondary system witha high priority level can be guaranteed first.

Frequency Spectral Management Method

It is apparent that some processing or methods are also disclosed in thedescription above on the frequency spectral management apparatus, thegeographical location database and the secondary system apparatusaccording to embodiments of the present invention. Below, the summary ofthe methods is described without repeating the details which are alreadydiscussed above, however, it should be noted that although disclosed inthe description of the frequency spectral management apparatus, thegeographical location database and the secondary system apparatus, themethods do not certainly employ or are not certainly executed by theaforementioned components. For instance, embodiments of the frequencyspectral management apparatus, the geographical location database andthe secondary system apparatus may be partially or completely achievedby hardware and/or firmware, and the frequency spectral managementmethods described below may be fully achieved by a computer-executableprogram, although the frequency spectral management methods may employthe hardware and/or firmware of the frequency spectral managementapparatus, the geographical location database and the secondary systemapparatus.

FIG. 12 shows the flowchart of the frequency spectral management methodin the cognitive radio system according to an embodiment of theinvention. Wherein, the cognitive radio system comprises a primarysystem, a first level secondary system, and a second level secondarysystem, the first level secondary system making use of frequencyspectral resources for the primary system with a higher priority levelthan the second level secondary system. As shown in FIG. 12, thefrequency spectral management method includes: receiving information ofa target secondary system requesting usage of the frequency spectralresources for the primary system (S11); acquiring pre-estimatedavailable frequency spectral for the target secondary system (S12); anddetermining adjustment with respect to the pre-estimated availablefrequency spectral for the target secondary system so as to determineavailable frequency spectral for the target secondary system, and/ordetermining adjustment with respect to the frequency spectral used byexisting second level secondary systems, according to the priority levelof the target secondary system (S13), and providing the adjustmentinformation to the corresponding secondary systems (S14).

Wherein, the requesting information can contain the related informationto the target secondary system, such as the priority level or ID of thecorresponding secondary system. If necessary, the related informationcan further include parameters such as the geographical location of thesystem.

When the target secondary system expects to make use of the frequencyspectral for the primary system, it sends the above requestinginformation. The pre-estimated available frequency spectral that can beprovided to the target secondary system is acquired in response to therequesting information. Such acquiring can be calculating directly, orcan be simply acquiring from a specialized storage apparatus orcomputing apparatus. In the case of calculating directly, the frequencyspectral management method further includes a step of acquiringinformation related to at least one of the primary system, the firstlevel secondary system and the second level secondary system. Therelated information includes geographical location of each system,frequency spectral used by each system and the priority level of eachsystem. As an example, this related information can be acquired from ageographical location database. In addition, the pre-estimated availablefrequency spectral for the target secondary system can also be acquireddirectly from the geographical location database.

In one embodiment, the step of acquiring the pre-estimated availablefrequency spectral includes acquiring the pre-estimated availablefrequency spectral under the condition that interference the primarysystem is subjected to is expected not to exceed an interferencethreshold for the primary system when the target secondary system makesuse of the frequency spectral resources for the primary system. Thepre-estimated available frequency spectral can be acquired with anyexisting technique.

However, the pre-estimated available frequency spectral might not betotally allocated to the target secondary system for use, which dependson the one hand the priority level of the target secondary system, andon the other hand, the situation of the frequency spectral usage of theexisting first level secondary systems. Therefore, to allocate thefrequency spectral resources reasonably, it is necessary to implementthe step S13 of frequency spectral adjusting.

Exemplarily, as shown by the solid lines in FIG. 13, the step S13 caninclude the following sub-steps: judging the priority level of thetarget secondary system (S131); calculating pre-estimated interferencesexisting first level secondary systems are subjected to when the targetsecondary system makes use of the frequency spectral resources for theprimary system in accordance with the pre-estimated available frequencyspectral therefor (S132); and determining adjustment with respect to thepre-estimated available frequency spectral for the target secondarysystem so as to determine the available frequency spectral therefor(S133).

Specifically, when the calculated pre-estimated interferences in thestep S132 exceed the interference thresholds for the existing firstlevel secondary system, frequency spectral less than the pre-estimatedavailable frequency spectral is determined as the available frequencyspectral for the target secondary system.

When the priority level of the target secondary system is judged to besecond level, since its priority level is low, it is only required toreduce the pre-estimated available frequency spectral for the targetsecondary system, in the case that the communication quality of theexisting first level secondary systems is necessary to be guaranteed.

When the priority level of the target secondary system is judged to befirst level, the step S13 of adjusting further includes determiningadjustment with respect to the frequency spectral used by the existingsecond level secondary systems on the basis of the requestinginformation of the target secondary system (S134). At this time, theflowchart of adjusting can be made reference to FIG. 14.

Specifically, in such a situation, since the priority level of thetarget secondary system is high, for example, its communication qualityshould be guaranteed. Therefore, the interferences caused by respectiveexisting secondary system to the target secondary system are calculatedfirst (S301), to judge whether the target secondary system can reach theexpected communication quality (S302). If the judging result is NO, itis checked whether there is adjustable existing second level secondarysystem(s) (S303). If YES, an existing second level secondary system tobe adjusted is selected (S304), and then the interferences the targetsecondary system to be subjected to are recalculated assuming thefrequency spectral used by this existing second level secondary systemis adjusted, until the target secondary system reaches the expectedcommunication quality or there is no adjustable second level secondarysystem.

Then, in step S305, it is judged whether the interferences the existingfirst level secondary systems are subjected to exceed a predeterminedthreshold when the target secondary system performs communication usingthe currently calculated available frequency spectral. If NO, theprocessing proceeds to S308 and the adjusting is ended. The targetsecondary system successfully requests the frequency spectral resources.

Otherwise, it is determined whether the current available frequencyspectral for the target secondary system is zero (S306). If it is notzero, this available frequency spectral is reduced (S307) and theprocessing proceeds to step S302. That is, it is determined whether thetarget secondary system can reach the expected communication quality inthe case of reducing the available frequency spectral resources. Again,if it can not reach the expected communication quality, the processingproceeds to step S303, S304 to further select an existing second levelsecondary system for adjusting.

On the other hand, if it is determined that the available frequencyspectral for the target secondary system is zero, indicating there is nofrequency spectral resources that can be allocated to the targetsecondary system, processing proceeds to step S309, and the flow ends.The target secondary system fails to request the frequency spectralresources.

Likewise, if no adjustable existing second level secondary system isfound in step S303, indicating that the target secondary system can notoperate normally in the case of not affecting the communication qualityof the existing first level secondary systems, processing proceeds tostep S309, and the target secondary system fails to request thefrequency spectral resources.

In addition, although not shown in FIG. 14, it should be understoodthat, a priority level adjusting step of changing the priority level ofthe target secondary system to be the second level can be furtherincluded, in the case that there is no adjustable second level secondarysystems and thus the target secondary system fails to request thefrequency spectral resources.

Wherein, in the step S304 of selecting a second level secondary systemto be adjusted in FIG. 14, a second level secondary system to beadjusted is selected according to the following principle: compared withreducing the frequency spectral used by the other second level secondarysystems among the existing second level secondary systems, the availablefrequency spectral for the target secondary system can be increased moreby reducing the frequency spectral used by this second level secondarysystem. Specifically, a second level secondary system to be adjusted canbe selected according to a path loss or a distance from the existingsecond level secondary system to a primary system reference point and apath loss or a distance from the existing second level secondary systemto the target secondary system.

After selecting a second level secondary system to be adjusted, thefrequency spectral used by the selected one or more second levelsecondary systems to be adjusted can be reduced by a fixed amount, orthe selected one or more second level secondary systems to be adjustedcan be stopped. Wherein, the adjusting can be implemented in real time.

As an example, in the above described cognitive radio system, theprimary system can be the television broadcast system. Further, thefirst level secondary system can be a mobile communication system withQuality of Service guarantee.

The basic principle of the present invention has been described above inconjunction with particular embodiments. However, as can be appreciatedby those ordinarily skilled in the art, all or any of the steps orcomponents of the method and apparatus according to the invention can beimplemented in hardware, firmware, software or a combination thereof inany computing device (including a processor, a storage medium, etc.) ora network of computing devices by those ordinarily skilled in the art inlight of the disclosure of the invention and making use of their generalprogramming skills.

Therefore, the present invention further discloses a program product inwhich machine-readable instruction codes are stored. The aforementionedmethods according to the embodiments can be implemented when theinstruction codes are read and executed by a machine.

Accordingly, a memory medium for carrying the program product in whichmachine-readable instruction codes are stored is also covered in thepresent invention. The memory medium includes but is not limited to softdisc, optical disc, magnetic optical disc, memory card, memory stick andthe like.

In the case where the present application is realized by software orfirmware, a program constituting the software is installed in a computerwith a dedicated hardware structure (e.g. the general computer 1500shown in FIG. 15) from a storage medium or network, wherein the computeris capable of implementing various functions when installed with variousprograms.

In FIG. 15, a computing processing unit (CPU) 1501 executes variousprocessing according to a program stored in a read-only memory (ROM)1502 or a program loaded to a random access memory (RAM) 1503 from astorage section 1508. The data needed for the various processing of theCPU 1501 may be stored in the RAM 1503 as needed. The CPU 1501, the ROM1502 and the RAM 1503 are linked with each other via a bus 1504. Aninput/output interface 1505 is also linked to the bus 1504.

The following components are linked to the input/output interface 1505:an input section 1506 (including keyboard, mouse and the like), anoutput section 1507 (including displays such as a cathode ray tube(CRT), a liquid crystal display (LCD), a loudspeaker and the like), astorage section 1508 (including hard disc and the like), and acommunication section 1509 (including a network interface card such as aLAN card, modem and the like). The communication section 1509 performscommunication processing via a network such as the Internet. A driver1510 may also be linked to the input/output interface 1505, if needed.If needed, a removable medium 1511, for example, a magnetic disc, anoptical disc, a magnetic optical disc, a semiconductor memory and thelike, may be installed in the driver 1510, so that the computer programread therefrom is installed in the memory section 1508 as appropriate.

In the case where the foregoing series of processing is achieved throughsoftware, programs forming the software are installed from a networksuch as the Internet or a memory medium such as the removable medium1511.

It should be appreciated by those skilled in the art that the memorymedium is not limited to the removable medium 1511 shown in FIG. 15,which has program stored therein and is distributed separately from theapparatus so as to provide the programs to users. The removable medium1511 may be, for example, a magnetic disc (including floppy disc(registered trademark)), a compact disc (including compact discread-only memory (CD-ROM) and digital versatile disc (DVD), a magnetooptical disc (including mini disc (MD)(registered trademark)), and asemiconductor memory. Alternatively, the memory medium may be the harddiscs included in ROM 1502 and the storage section 1508 in whichprograms are stored, and can be distributed to users along with thedevice in which they are incorporated.

To be further noted, in the apparatus, method and system according tothe invention, the respective components or steps can be decomposedand/or recombined. These decompositions and/or recombinations shall beregarded as equivalent solutions of the invention. Moreover, the aboveseries of processing steps can naturally be performed temporally in thesequence as described above but will not be limited thereto, and some ofthe steps can be performed in parallel or independently from each other.

Finally, to be further noted, the term “include”, “comprise” or anyvariant thereof is intended to encompass nonexclusive inclusion so thata process, method, article or device including a series of elementsincludes not only those elements but also other elements which have beennot listed definitely or an element(s) inherent to the process, method,article or device. Moreover, the expression “comprising a(n) . . . ” inwhich an element is defined will not preclude presence of an additionalidentical element(s) in a process, method, article or device comprisingthe defined element(s)” unless further defined.

Although the embodiments of the invention have been described above indetail in connection with the drawings, it shall be appreciated that theembodiments as described above are merely illustrative but notlimitative of the invention. Those skilled in the art can make variousmodifications and variations to the above embodiments without departingfrom the spirit and scope of the invention. Therefore, the scope of theinvention is defined merely by the appended claims and theirequivalents.

The embodiments disclosed herein may be configured as below.

According to one exemplary embodiment, the disclosure is directed to asystem comprising: circuitry configured to receive a request forresources from a first system of a plurality of systems having differentlevels of priority; identify resources that are available in a secondsystem different from the plurality of systems based on the receivedrequest; and determine whether to adjust a resource assigned to theplurality of systems based on the priority level of the first system andthe resources that are available in the second system.

According to the above system, the resources that are available in thesecond system are resources that are initially assigned for use by thesecond system and not initially assigned for use by the plurality ofsystems.

According to the above system, the second system is a televisionbroadcast system operating in a ultra-high frequency (UHF) band, and thecircuitry is configured to identify, as the resources that are availablein the second system, at least at subset of the UHF band.

According to the above system, the circuitry is configured to identifythe resources that are available in the second system by identifyingresources assigned to the second system that could be used by the firstsystem without causing interference in the second system above apredetermined threshold.

According to the above system, the circuitry is configured to: estimatea level of interference caused to the second system when the resourcesthat are available in the second system are reassigned to the firstsystem; and determine whether to adjust a resource assigned to the firstsystem based on the estimated level of interference.

According to the above system, the circuitry is configured to: estimatea level of interference caused to a third system of the plurality ofsystems when the resources that are available in the second system arereassigned to the first system; and determine whether to adjust aresource assigned to the first system based on the estimated level ofinterference.

According to the above system, the request includes informationindicating a geographic location of the first system, and the circuitryis configured to identify the resources that are available in the secondsystem based on the geographic location of the first system.

According to the above system, the request includes informationidentifying the level of priority of the first system.

According to the above system, the plurality of systems includes thefirst system having a first level of priority for accessing resources ofthe second system and a third system having a second level of priorityfor accessing resources of the second system, the second level ofpriority being greater than the first level of priority.

According to the above system, the circuitry is configured to estimate alevel of interference to the third system if the resources that areavailable in the second system were to be assigned to the first system.

According to the above system, the circuitry is configured to assign theresources that are available in the second system to the first systemwhen estimated level of interference to the third system does not exceeda predetermined threshold value.

According to the above system, the circuitry is configured to controladjusting the resources that are available to the first system when theestimated level of interference to the third system exceeds apredetermined threshold value.

According to the above system, the plurality of systems includes thefirst system having a first level of priority for accessing resources ofthe second system and a third system having a second level of priorityfor accessing resources of the second system, the first level ofpriority being greater than the second level of priority.

According to the above system, the request for resources from the firstsystem includes information indicating at least one of a desiredcommunication quality, a desired communication range and a tolerableinterference threshold in the first system, and the circuitry isconfigured to identify the resources that are available in a secondsystem based on the information included in the received request.

According to the above system, the circuitry is configured to determinea level of interference to the first system by the third system if theresources that are available in the second system were to be assigned tothe first system.

According to the above system, the circuitry is configured to assign theresources that are available in the second system to the first systemand not control adjusting resources assigned to the third system whenthe determined level of interference to the first system by the thirdsystem does not exceed a predetermined threshold value.

According to the above system, the circuitry is configured to assign theresources that are available in the second system to the first systemand control adjusting resources assigned to the third system to reduceinterference to the first system when the determined level ofinterference to the first system by the third system exceeds apredetermined threshold value.

According to the above system, the plurality of systems includes thefirst system having a first level of priority for accessing resources ofthe second system, and third and fourth systems each having a level ofpriority for accessing resources of the second system that is less thanthe first level of priority; and the circuitry is configured todetermine a level of interference to the first system if the resourcesthat are available in the second system were to be assigned to the firstsystem; assign the resources that are available in the second system tothe first system and control adjusting resources assigned to at leastone of the third and fourth systems determined to cause a higher amountof interference to the first system when the determined level ofinterference to the first system exceeds a predetermined thresholdvalue.

According to the above system, the circuitry is configured to identifythe resources that are available in the second system based oninformation identifying the resources received from a database remotelyconnected to the system.

According to another exemplary embodiment, the disclosure is directed toa non-transitory computer-readable medium including computer-readableinstructions, which when executed by a system, cause the system to:receive a request for resources from a first system of a plurality ofsystems having different levels of priority; identify resources that areavailable in a second system different from the plurality of systemsbased on the received request; and determine whether to adjust aresource assigned to the plurality of systems based on the prioritylevel of the first system and the resources that are available in thesecond system.

According to another exemplary embodiment, the disclosure is directed toa system comprising: circuitry configured to receive a request forresources from a first system of a plurality of systems having differentlevels of priority; transmit, to another system, information identifyingresources that are available in a second system different from theplurality of systems based on the received request; and receive, fromthe another system, information requesting to adjust a resource assignedto the plurality of systems based on the priority level of the firstsystem and the resources that are available in the second system.

According to another exemplary embodiment, the disclosure is directed toa frequency spectral management apparatus in a cognitive radio system,wherein, the cognitive radio system comprises a primary system, a firstlevel secondary system, and a second level secondary system, the firstlevel secondary system making use of frequency spectral resources forthe primary system with a higher priority level than the second levelsecondary system, the frequency spectral management apparatuscomprising: a communication unit, configured to receive information of atarget secondary system requesting usage of the frequency spectralresources for the primary system; an available frequency spectralacquiring unit, configured to acquire pre-estimated available frequencyspectral for the target secondary system; and a frequency spectral usageadjusting unit, configured to determine adjustment with respect to thepre-estimated available frequency spectral for the target secondarysystem so as to determine available frequency spectral for the targetsecondary system, and/or determine adjustment with respect to thefrequency spectral used by existing second level secondary systems,according to the priority level of the target secondary system.

The above apparatus, further comprising a storage unit, configured tostore information related to at least one of the primary system, thefirst level secondary system and the second level secondary system,wherein, the related information comprises geographical location of eachsystem, frequency spectral used by each system and the priority level ofeach system.

The above apparatus, further comprising a system information acquiringunit, configured to acquire information related to at least one of theprimary system, the first level secondary system and the second levelsecondary system from outside, wherein, the related informationcomprises geographical location of each system, frequency spectral usedby each system and the priority level of each system.

According to the above apparatus, the related information regarding thetarget secondary system is contained in information of the targetsecondary system requesting the usage of the frequency spectralresources for the primary system.

According to the above apparatus, the available frequency spectralacquiring unit is configured to acquire the pre-estimated availablefrequency spectral under a condition that interference the primarysystem is subjected to is expected not to exceed an interferencethreshold for the primary system when the target secondary system makesuse of the frequency spectral resources for the primary system.

According to the above apparatus, the frequency spectral usage adjustingunit comprises: a system priority level judging module, configured tojudge the priority level of the target secondary system; an interferencecalculating module, configured to calculate pre-estimated interferencesexisting first level secondary systems are subjected to when the targetsecondary system makes use of the frequency spectral resources for theprimary system in accordance with the pre-estimated available frequencyspectral therefor; and an adjusting module, configured to determineadjustment with respect to the pre-estimated available frequencyspectral for the target secondary system so as to determine theavailable frequency spectral therefor.

According to the above apparatus, the adjusting module determinesfrequency spectral less than the pre-estimated available frequencyspectral as the available frequency spectral for the target secondarysystem, in the case that the pre-estimated interferences calculated bythe interference calculating module exceed interference thresholds forthe existing first level secondary systems.

According to the above apparatus, the adjusting module is furtherconfigured to determine adjustment with respect to the frequencyspectral used by the existing second level secondary systems on thebasis of the information of the target secondary system requesting theusage of the frequency spectral resources for the primary system, in thecase that the system priority level judging module judges that thetarget secondary system is a first level secondary system.

According to the above apparatus, the adjusting module is configured toselect a second level secondary system to be adjusted according to thefollowing principle: compared with reducing the frequency spectral usedby the other second level secondary systems among the existing secondlevel secondary systems, the available frequency spectral for the targetsecondary system can be increased more by reducing the frequencyspectral used by this second level secondary system.

According to the above apparatus, the adjusting module is configured toreduce the frequency spectral used by the selected one or more secondlevel secondary systems to be adjusted by a fixed amount, or stop theone or more second level secondary systems.

According to the above apparatus, the adjusting module is configured toselect a second level secondary system to be adjusted according to apath loss or a distance from the existing second level secondary systemto a primary system reference point and a path loss or a distance fromthe existing second level secondary system to the target secondarysystem.

According to the above apparatus, the primary system is the televisionbroadcast system.

According to the above apparatus, the frequency spectral usage adjustingunit is further configured to adjust the frequency spectral usage of thecorresponding existing second level secondary systems according to thedetermined adjustment with respect to the frequency spectral used by theexisting second level secondary systems.

According to another exemplary embodiment, the disclosure is directed toa geographical location database in a cognitive radio system, wherein,the cognitive radio system comprises a primary system, a first levelsecondary system, and a second level secondary system, the first levelsecondary system making use of frequency spectral resources for theprimary system with a higher priority level than the second levelsecondary system, the geographical location database comprising: acommunication part, configured to receive information of a targetsecondary system requesting usage of the frequency spectral resourcesfor the primary system; an available frequency spectral calculatingpart, configured to calculate pre-estimated available frequency spectralfor the target secondary system in response to the information; and astorage part, configured to store information related to the primarysystem, the first level secondary system and the second level secondarysystem, wherein, the communication part transmits at least thepre-estimated available frequency spectral to a frequency spectralmanagement apparatus in the cognitive radio system, and receivesinformation related to adjustment with respect to the pre-estimatedavailable frequency spectral for the target secondary system and/orinformation related to adjustment with respect to the frequency spectralused by the existing second level secondary systems determined by thefrequency spectral management apparatus according to a priority level ofthe target secondary system.

According to the above geographical location database, the informationrelated to the determined adjustment with respect to the frequencyspectral used by the existing second level secondary systems is afrequency spectral usage adjusting command containing the determinedadjustment with respect to the frequency spectral used by the existingsecond level secondary systems, and the geographical location databasefurther comprises a frequency spectral usage adjusting unit, which isconfigured to adjust the frequency spectral usage of the correspondingexisting second level secondary systems according to the frequencyspectral usage adjusting command.

The above geographical location database, further comprising: a periodof validity setting part, configured to set a period of validity for thepre-estimated available frequency spectral resources for each secondlevel secondary system according to the demand for frequency spectral ofthe primary system, and divide the period of validity into a pluralityof valid time sections; and a timer, configured to perform timing sothat the geographical location database determines the availablefrequency spectral resources for each second level secondary system atthe time each valid time section expires, and performs adjusting to thefrequency spectral used by the corresponding second level secondarysystems based on the information related to the adjustment.

According to another exemplary embodiment, the disclosure is directed toa secondary system apparatus in a cognitive radio system, wherein, thecognitive radio system comprises a primary system, a first levelsecondary system, and a second level secondary system, the first levelsecondary system making use of frequency spectral resources for theprimary system with a higher priority level than the second levelsecondary system, the secondary system apparatus is provided in thefirst level secondary system or in the second level secondary system,the secondary system apparatus comprising: a communication unit,configured to transmit requesting information of requesting usage of thefrequency spectral resources for the primary system, the requestinginformation containing information about a priority level of thesecondary system apparatus, and receive available frequency spectralinformation for the secondary system apparatus determined according tothe priority level; and a frequency spectral using unit, configured tomake use of the frequency spectral resources for the primary systemaccording to the available frequency spectral information received bythe communication unit.

According to the above secondary system apparatus, the communicationunit is further configured to receive frequency spectral usage adjustinginformation regarding the secondary system apparatus when the secondarysystem apparatus is corresponding to a second level secondary system,the frequency spectral usage adjusting information being determinedaccording to the requesting information of the first level secondarysystem in the cognitive radio system requesting the usage of thefrequency spectral resources for the primary system.

According to another exemplary embodiment, the disclosure is directed toa frequency spectral management system for managing frequency spectralusage in a cognitive radio system, wherein, the cognitive radio systemcomprises a primary system, a first level secondary system, and a secondlevel secondary system, the first level secondary system making use offrequency spectral resources for the primary system with a higherpriority level than the second level secondary system, the frequencyspectral management system comprising: a frequency spectral managementapparatus, comprising: a communication unit, configured to receiveinformation of a target secondary system requesting usage of thefrequency spectral resources for the primary system; an availablefrequency spectral acquiring unit, configured to acquire pre-estimatedavailable frequency spectral for the target secondary system; and afrequency spectral usage adjusting unit, configured to determineadjustment with respect to the pre-estimated available frequencyspectral for the target secondary system so as to determine availablefrequency spectral for the target secondary system, and/or determineadjustment with respect to the frequency spectral used by existingsecond level secondary systems, according to the priority level of thetarget secondary system, a geographical location database, comprising: acommunication part, configured to receive information of a targetsecondary system requesting the usage of the frequency spectralresources for the primary system; an available frequency spectralcalculating part, configured to calculate pre-estimated availablefrequency spectral for the target secondary system in response to theinformation; and a storage part, configured to store information relatedto the primary system, the first level secondary system and the secondlevel secondary system, and a secondary system apparatus, comprising: acommunication unit, configured to transmit requesting information ofrequesting the usage of the frequency spectral resources for the primarysystem, the requesting information containing information about apriority level of the secondary system apparatus, and receive availablefrequency spectral information for the secondary system apparatusdetermined according to the priority level; and a frequency spectralusing unit, configured to make use of the frequency spectral resourcesfor the primary system according to the available frequency spectralinformation received by the communication unit, wherein, thecommunication part in the geographical location database transmits atleast the pre-estimated available frequency spectral to the frequencyspectral management apparatus, and receives information related toadjustment with respect to the pre-estimated available frequencyspectral for the target secondary system and/or information related toadjustment with respect to the frequency spectral used by the existingsecond level secondary systems determined by the frequency spectralmanagement apparatus according to the priority level of the targetsecondary system.

According to another exemplary embodiment, the disclosure is directed toa frequency spectral management method in a cognitive radio system,wherein, the cognitive radio system comprises a primary system, a firstlevel secondary system, and a second level secondary system, the firstlevel secondary system making use of frequency spectral resources forthe primary system with a higher priority level than the second levelsecondary system, the frequency spectral management method comprising:receiving information of a target secondary system requesting usage ofthe frequency spectral resources for the primary system; acquiringpre-estimated available frequency spectral for the target secondarysystem; and determining adjustment with respect to the pre-estimatedavailable frequency spectral for the target secondary system so as todetermine available frequency spectral for the target secondary system,and/or determining adjustment with respect to the frequency spectralused by existing second level secondary systems, according to thepriority level of the target secondary system, and providing theadjustment information to the corresponding secondary systems.

The above frequency spectral management method further comprising:acquiring information related to at least one of the primary system, thefirst level secondary system and the second level secondary system,wherein, the related information comprises geographical locations ofeach system, frequency spectral used by each system and priority levelsof each system.

According to the above frequency spectral management method, the relatedinformation regarding the target secondary system being contained ininformation of the target secondary system requesting the usage of thefrequency spectral resources for the primary system.

The above frequency spectral management method, the step of acquiringthe pre-estimated available frequency spectral comprises acquiring thepre-estimated available frequency spectral under the condition thatinterference the primary system is subjected to is expected not toexceed an interference threshold for the primary system when the targetsecondary system makes use of the frequency spectral resources for theprimary system.

The above frequency spectral management method, the step of adjustingcomprising: judging the priority level of the target secondary system;calculating pre-estimated interferences existing first level secondarysystems are subjected to when the target secondary system makes use ofthe frequency spectral resources for the primary system in accordancewith the pre-estimated available frequency spectral therefor; anddetermining adjustment with respect to the pre-estimated availablefrequency spectral for the target secondary system so as to determinethe available frequency spectral therefor.

According to the above frequency spectral management method, determiningfrequency spectral less than the pre-estimated available frequencyspectral as the available frequency spectral for the target secondarysystem, in the case that the pre-estimated interferences exceedinterference thresholds for the existing first level secondary systems.

The above frequency spectral management method, wherein determiningadjustment with respect to the frequency spectral used by the existingsecond level secondary systems on the basis of the requestinginformation of the target secondary system, in the case that the targetsecondary system is judged to be a first level secondary system.

1. A system comprising: circuitry configured to receive a request forresources from a first system of a plurality of systems having differentlevels of priority; identify resources that are available in a secondsystem different from the plurality of systems based on the receivedrequest; and determine whether to adjust a resource assigned to theplurality of systems based on the priority level of the first system andthe resources that are available in the second system.
 2. The system ofclaim 1, wherein the resources that are available in the second systemare resources that are initially assigned for use by the second systemand not initially assigned for use by the plurality of systems.
 3. Thesystem of claim 1, wherein the second system is a television broadcastsystem operating in a ultra-high frequency (UHF) band, and the circuitryis configured to identify, as the resources that are available in thesecond system, at least at subset of the UHF band.
 4. The system ofclaim 1, wherein the circuitry is configured to identify the resourcesthat are available in the second system by identifying resourcesassigned to the second system that could be used by the first systemwithout causing interference in the second system above a predeterminedthreshold.
 5. The system of claim 1, wherein the circuitry is configuredto: estimate a level of interference caused to the second system whenthe resources that are available in the second system are reassigned tothe first system; and determine whether to adjust a resource assigned tothe first system based on the estimated level of interference.
 6. Thesystem of claim 1, wherein the circuitry is configured to: estimate alevel of interference caused to a third system of the plurality ofsystems when the resources that are available in the second system arereassigned to the first system; and determine whether to adjust aresource assigned to the first system based on the estimated level ofinterference.
 7. The system of claim 1, wherein the request includesinformation indicating a geographic location of the first system, andthe circuitry is configured to identify the resources that are availablein the second system based on the geographic location of the firstsystem.
 8. The system of claim 1, wherein the request includesinformation identifying the level of priority of the first system. 9.The system of claim 1, wherein the plurality of systems includes thefirst system having a first level of priority for accessing resources ofthe second system and a third system having a second level of priorityfor accessing resources of the second system, the second level ofpriority being greater than the first level of priority.
 10. The systemof claim 9, wherein the circuitry is configured to estimate a level ofinterference to the third system if the resources that are available inthe second system were to be assigned to the first system.
 11. Thesystem of claim 10, wherein the circuitry is configured to assign theresources that are available in the second system to the first systemwhen estimated level of interference to the third system does not exceeda predetermined threshold value.
 12. The system of claim 10, wherein thecircuitry is configured to control adjusting the resources that areavailable to the first system when the estimated level of interferenceto the third system exceeds a predetermined threshold value.
 13. Thesystem of claim 1, wherein the plurality of systems includes the firstsystem having a first level of priority for accessing resources of thesecond system and a third system having a second level of priority foraccessing resources of the second system, the first level of prioritybeing greater than the second level of priority.
 14. The system of claim13, wherein the request for resources from the first system includesinformation indicating at least one of a desired communication quality,a desired communication range and a tolerable interference threshold inthe first system, and the circuitry is configured to identify theresources that are available in a second system based on the informationincluded in the received request.
 15. The system of claim 13, whereinthe circuitry is configured to determine a level of interference to thefirst system by the third system if the resources that are available inthe second system were to be assigned to the first system.
 16. Thesystem of claim 15, wherein the circuitry is configured to assign theresources that are available in the second system to the first systemand not control adjusting resources assigned to the third system whenthe determined level of interference to the first system by the thirdsystem does not exceed a predetermined threshold value.
 17. The systemof claim 15, wherein the circuitry is configured to assign the resourcesthat are available in the second system to the first system and controladjusting resources assigned to the third system to reduce interferenceto the first system when the determined level of interference to thefirst system by the third system exceeds a predetermined thresholdvalue.
 18. The system of claim 1, wherein the plurality of systemsincludes the first system having a first level of priority for accessingresources of the second system, and third and fourth systems each havinga level of priority for accessing resources of the second system that isless than the first level of priority; and the circuitry is configuredto determine a level of interference to the first system if theresources that are available in the second system were to be assigned tothe first system; assign the resources that are available in the secondsystem to the first system and control adjusting resources assigned toat least one of the third and fourth systems determined to cause ahigher amount of interference to the first system when the determinedlevel of interference to the first system exceeds a predeterminedthreshold value.
 19. The system of claim 1, wherein the circuitry isconfigured to identify the resources that are available in the secondsystem based on information identifying the resources received from adatabase remotely connected to the system.
 20. A non-transitorycomputer-readable medium including computer-readable instructions, whichwhen executed by a system, cause the system to: receive a request forresources from a first system of a plurality of systems having differentlevels of priority; identify resources that are available in a secondsystem different from the plurality of systems based on the receivedrequest; and determine whether to adjust a resource assigned to theplurality of systems based on the priority level of the first system andthe resources that are available in the second system.
 21. A systemcomprising: circuitry configured to receive a request for resources froma first system of a plurality of systems having different levels ofpriority; transmit, to another system, information identifying resourcesthat are available in a second system different from the plurality ofsystems based on the received request; and receive, from the anothersystem, information requesting to adjust a resource assigned to theplurality of systems based on the priority level of the first system andthe resources that are available in the second system.